The electrical supply of a sensor is generally achieved by means of a voltage or current with constant and predetermined characteristics. This configuration enables a constant mean power to be applied to the sensor terminals. Sensor manufacturers recommend a supply at a constant voltage or current for the sensors' entire duration of supply.
The use of a current regulation diode provides a current or voltage with constant characteristics at the sensor's terminals and thus enables a constant mean power to be applied.
On observing the values returned by a measurement sensor when it is switched on, it will be noted that these values take a certain time to stabilise. As a general rule, the values returned by the sensor increase until reaching a maximum value then decrease to reach an asymptotic value, as shown in FIG. 1. During its stabilisation phase, the sensor consumes energy whereas the values that it returns are not useable. This involves a not inconsiderable consumption of energy during the stabilisation phase.
There are some industrial devices that enable measurements to be made and sent wirelessly such as the EAGLE solution developed by the Acoem Company.
However, these solutions do not specifically address the problem of energy consumption during the sensor stabilisation phase. The life of the independent power supply is therefore affected.
One generally adopted solution to this technical problem consists in optimising the components in order to obtain a less energy-consuming solution and in particular using more sophisticated and more costly sensors in order to save energy and thus preserve the life of the energy source.